<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <link href="../../template/img/page-logo.png" rel="icon" type="image/png" />
    <title>IFE JavaScript Task 01</title>
  </head>
<body>

  <label>请输入北京今天空气质量：<input id="aqi-input" type="text"></label>
  <button id="button">确认填写</button>

  <div>您输入的值是：<span id="aqi-display">尚无录入</span></div>

<script type="text/javascript">

  var input=document.getElementById("aqi-input");
  var button=document.getElementById("button");
  var display=document.getElementById("aqi-display");
  
  function show(){
    display.innerHTML = input.value;
  }
  button.onclick= show;
  

</script>
</body>
</html>